Project Summary/Abstract Non-invasive brain stimulation (NIBS) has attracted considerable interest in the cognitive neuroscience community, providing an important basic research tool to study brain function, with emerging clinical applications to enhance cognitive function in individuals with neurological disorders. Despite this potential, an emerging literature has highlighted concerns regarding the reliability and robustness of transcranial electric stimulation (tES), the primary NIBS method used to induce changes in brain plasticity through the application of subthreshold stimulation. These problems are likely related to the fact that tES systems can only induce modest electrical fields (E-field) at the cortical surface given that safety/tolerance issues limit the intensity of tES stimulation that can be delivered at the scalp. We propose to develop a radically new NIBS device, one in which we will apply oscillating magnetic fields at kHZ frequencies. Theoretical analyses indicate that this device will produce a significant increase in the range of E-field induction, as well as provide a number of other advantages, relative to current NIBS methods. The two-year funding period will be used to perform the theoretical analysis of the system, construct the device to deliver kHz magnetic stimulation, perform bench tests to confirm theoretical estimates, and conduct initial testing with human participants to assess the feasibility of the system for producing changes in cortical physiology. If our expectations are confirmed, this system will provide a powerful new tool for modulating neural excitability.